During surgery or preparatory to surgery, a surgeon may need to determine the surface topography of the tissue to be operated on. As an example, orthopedic surgeons may need to determine the surface of bones which may need to be operated on. In some cases, a surgeon may need to digitize the surface of a patient's bone in order to make measurements, or to apply a pre-operative plan for computer-assisted surgery. A pre-operative plan might be the desired location of a bone cut or the final location of an implant, or any number of desired outcomes.
A pre-operative plan is usually determined using a CT (computed-tomography) scan or MRI (magnetic resonance image) of the patient's anatomy. The pre-operative plan can include desired changes to the anatomy, or navigational marks, or it can include a virtual representation of an implant in the desired final location. In computer-assisted surgery, an important step is to transfer the pre-operative plan to the patient's anatomy during the surgery, so that the surgeon can view it on a monitor and so that the navigational software can correlate the plan to the patient. Currently, such computer- or robot-assisted surgical protocols for orthopaedic surgery utilize a long physical contact stylus to digitize the bone surface. This process requires an unobstructed view of the entire bony surface, which necessitates a large surgical opening. For many reasons, large surgical openings are not desired and current surgical trends are toward minimally invasive surgery.
Based on the above, there is therefore a need for systems, methods, or devices which allows surgeons to map the topography of areas which may be operated on. Specifically, there is a need for such technologies which do not involve large surgical openings.